1. Field of the Invention
This invention relates to roof flashing units and both the apparatus and method of making them and, more particularly, to the use of ultrasonic welding apparatus for making the roof flashing units.
2. Description of the Prior Art
The use of ultrasonic welding is well known and understood in the art of joining materials. Ultrasonic welding apparatus has been used to join sheet material, as illustrated in U.S. Pat. No. 4,208,001 (Martner), U.S. Pat. No. 4,525,233 (Brooks), and U.S. Pat. No. 4,737,213 (Paeglis and Hinckley). Ultrasonic welding apparatus and techniques have also been used to weld window frames, as illustrated in U.S. Pat. No. 4,856,230 (Slocum) and U.S. Pat. No. 5,105,581 (Slocum, Jr.).
U.S. Pat. No. 5,846,377 (Frantz et al) is a patent which refers to the welding of thermoplastic elements.
U.S. Pat. No. 5,902,657 (Hanson) discloses the use of ultrasonic welding for making window and door joints.
Roof flashing units of the prior art are typically made of aluminum and use rivets to secure their seams. There are also mechanical overlap seams. However, the seams always have leaked, and the need for caulking was obvious. However, caulking cannot be used for flat roofs, where heat from hot asphalt being applied melts the caulk. Roof flashing units include a cylinder secured to a flat plate, and both the seam of the cylinder and the seam required to secure the cylinder to the flat base plate cause leakage problems over time with respect to the caulk.
There are generally three types of roof flashing units, a pipe jack type, which typically goes over sewer pipes extending upwardly from the roof. A second roof flashing type is pipe flashing which typically is disposed over the flue of a gas burning appliance, such as type B gas appliances, namely hot water heaters, gas furnaces, etc. The third type of roof flashing units is the tee top. These units go over or about flues from fans which blow air out of houses, such as exhaust fans, where no heat is involved, and the like.
Pipe jacks generally include a base element and a pipe which extends generally perpendicular to the base element.
Pipe flashing units typically include a base unit and a pipe which is larger than the pipe jack and which typically includes a slant or taper of some type. The pipe element is secured to the base element.
A tee top includes a base unit, a pipe which may or may not have a slant to it, and a curved half cylinder panel secured to the top of the pipe to prevent rain from flowing downwardly.
The method and apparatus comprising the present invention is capable of making all three types of roof flashing units.
With the apparatus and method of the present invention, aluminum roof flashing units are ultrasonically welded, and thus the problem of the riveted seams, or the other type of seams is substantially eliminated. The tubular or cylindrical pipe element is secured to the flat base element by means of ultrasonic welding, thus allowing the roof flashing units to be used on both flat roofs and on sloping roofs.
The invention described and claimed herein includes a method for ultrasonically welding a pipe element, and for securing the ultrasonically welded pipe element to a base plate. When the pipe element and the base plate are ultrasonically welded together, a roof flashing unit is completed. The roof flashing unit is typically made of aluminum, and the aluminum parts or elements are ultrasonically welded by two ultrasonic welding units or apparatus. The two ultrasonic welders include an anvil element which is freely rotating but does move perpendicular to its rotation axis, and a horn unit against which the aluminum material is disposed and against which the aluminum is pressed during the ultrasonic welding procedure. The ultrasonic welding apparatus for ultrasonically welding the tubular element is generally horizontally disposed, while the ultrasonic welding apparatus for joining the cylindrical pipe element to the base plate is generally vertically oriented.
Among the objects of the present invention are the following:
To provide new and useful roof flashing units which are ultrasonically welded;
To provide new and useful aluminum roof flashing units;
To provide a pair of ultrasonic welders for welding roof flashing units;
To provide an ultrasonic welder for welding a tubular aluminum element;
To provide a ultrasonic welder for joining a flat base plate to a tubular pipe member; and
To provide new and useful apparatus for ultrasonically welding roof flashing units.